Whether it was technical or mental - Janikowski had gotten used to Shane Lechler holding for him for 13 seasons - the missed field-goal tries were a surprising problem for the Raiders.

After making 62 of 69 field- goal attempts (90 percent) the previous two seasons, Janikowski made 21 0f 30 (70 percent) last season. He missed two inside the 40-yard line, more than he had missed from that distance the previous five seasons combined.

The Raiders might have been able to boost their win total from four to six last season if not for the miscues, so they made it a priority this offseason. They hired a kicking coach, assistant special-teams coach Chris Boniol, for the first time since Buggsy Engleberg was tapped in 1968.

"Progress has been made in that area this offseason," general manager Reggie McKenzie said. "Boniol's been really working with them on the particulars. And being an ex-kicker, he understands the psyche that you have to have,"

Boniol, who kicked six years in the NFL for the Cowboys, Eagles and Bears, had Janikowski and King, the punter, arrive two months early to work on holding and kicking.

"We broke it down by every small piece and worked very hard on fundamentals," Boniol said. "I was so pleased by how hard those guys worked. They invested a lot of energy and effort."

Boniol talked about how much kickers are creatures of habit, and even the smallest change can disrupt things. "It doesn't even matter sometimes what the replacement part is," he said.

Also, remember that last year at this time, King was competing with Chris Kluwe for the starting job and Kluwe was doing a lot of the holding for Janikowski.

Janikowski, meanwhile, has come into camp in seemingly better shape every year the past few seasons, and he thinks the extra work with King will pay off.

"With Shane, we knew each other so well, that's a trust issue right there," said Janikowski, 36. "He knew if I'm pushing the ball, he would tilt the ball in the different direction. So now I'm working with Marquette, and it's improving a lot."

King, after his initial bout of amnesia, later said he is "confident" the two are on the same page, and he has been working on holding the ball with one finger as opposed to three - something he thinks will help Janikowski see the ball better.

"Whether it's one or three fingers, the bottom line is control the ball," Boniol said. "Give the kicker good vision. So we've talked about body position, we've talked about the angle of the arm, what are the hands doing ... your demeanor on the field.

"Then, hundreds and hundreds of reps in the offseason. And maybe looking at the kicker's angles."

Everyone at training camp in Napa is confident about the situation going into Friday's preseason opener in Minnesota, but Janikowski and King won't have as long a rope as they had last season. Quarterbacks Derek Carr and Matt McGloin have gotten some work in holding for Janikowski as well.

"It's going to come down to a comfort level with Sebastian," Raiders head coach Dennis Allen said, "because he has to be able to trust that the ball's going to be put down and held in the right manner and in the right position to where he can just go out there and kick.

"And not thinking about what it looks like."

Boniol is confident that will happen.

"They're both very talented," he said. "And when you put all that hard work together with talent, you have a good chance. They've had an opportunity to build some continuity now."

Ausberry needs surgery

David Ausberry needs knee surgery, head coach Dennis Allen said after Tuesday's practice. Ausberry will miss Friday's preseason opener against Minnesota. The tight end was atop the depth chart after a week at training camp.

Allen didn't disclose the exact nature of the injury or what knee Ausberry hurt. The 2011 seventh-round pick had missed the past two practices. Ausberry missed all of last season with a shoulder injury.

Second-year player Mychal Rivera, who offensive coordinator Greg Olson said was one of the most improved players in camp, moves up to the first team. Rivera had 38 catches for 407 yards and four touchdowns his rookie year and has worked hard on his blocking.